Department of Orthopaedic Surgery, Niigata Medical Center, Niigata, Japan.
Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, Niigata, Japan.
Biomed Mater Eng. 2021;32(3):183-194. doi: 10.3233/BME-201209.
Assessment of three-dimensional (3D) femorotibial alignment is essential for successful knee osteoarthritis treatment in the elderly. The complex morphology of the posterior tibial slope (PTS) might have an influence on sagittal and rotational alignment and the positional relationship between the femur and tibia in the anterior-posterior (AP) direction under weight-bearing conditions.
This study aimed to clarify the association between the PTS and 3D femorotibial alignment under weight-bearing conditions in healthy Japanese elderly individuals.
We investigated the 3D femorotibial alignment of 110 lower extremities of 55 healthy individuals (26 women, 29 men, mean age: 70 ± 6 years). Using our previously reported 3D-to-2D image registration technique, we evaluated the 3D hip-knee-ankle angle (3DHKA) in the sagittal plane, rotational alignment, and the distance between the femoral and tibial origins in the AP direction (tibial AP position) as femorotibial alignment parameters under weight-bearing conditions. We assessed the medial and lateral PTS and their angular difference (PTS difference) as PTS parameters. Stepwise multiple linear regression analysis was performed using PTS parameters and other possible confounders (age, sex, height, and weight) as the independent variables and femorotibial alignment parameters as the dependent variable.
Weight (𝛽 = 0.393, p < 0.001) and lateral PTS (𝛽 = 0.298, p < 0.001) were the predictors associated with 3DHKA in the sagittal plane. Lateral PTS (𝛽 = 0.304, p = 0.001) was the only predictor associated with the tibial AP position. Sex (𝛽 = -0.282, p = 0.002) and PTS difference (𝛽 = -0.231, p = 0.012) were associated with rotational alignment.
We found that a steeper lateral PTS resulted in a more flexed knee and anterior tibia. The PTS difference was positively correlated with tibial external rotation. Our data could be used as the standard reference for realignment surgery to ensure PTS is appropriately maintained.
评估三维（3D）股骨胫骨对线对于老年膝骨关节炎的成功治疗至关重要。胫骨后倾角（PTS）的复杂形态可能会影响负重条件下矢状面和旋转对线以及股骨和胫骨在前后（AP）方向上的位置关系。
本研究旨在阐明负重条件下健康日本老年人 PTS 与 3D 股骨胫骨对线之间的关系。
我们研究了 55 名健康个体（26 名女性，29 名男性，平均年龄：70±6 岁）的 110 条下肢的 3D 股骨胫骨对线。使用我们之前报道的 3D 到 2D 图像配准技术，我们评估了矢状面中的 3D 髋膝踝角（3DHKA）、旋转对线以及在负重条件下 AP 方向上股骨和胫骨起点之间的距离（胫骨 AP 位置）作为股骨胫骨对线参数。我们评估了内侧和外侧 PTS 及其角度差异（PTS 差异）作为 PTS 参数。使用 PTS 参数和其他可能的混杂因素（年龄、性别、身高和体重）作为自变量，股骨胫骨对线参数作为因变量，进行逐步多元线性回归分析。
体重（β=0.393，p<0.001）和外侧 PTS（β=0.298，p<0.001）是与矢状面 3DHKA 相关的预测因子。外侧 PTS（β=0.304，p=0.001）是与胫骨 AP 位置相关的唯一预测因子。性别（β=-0.282，p=0.002）和 PTS 差异（β=-0.231，p=0.012）与旋转对线相关。
我们发现外侧 PTS 更陡峭会导致膝关节更弯曲和胫骨更靠前。PTS 差异与胫骨外旋呈正相关。我们的数据可作为重新对线手术的标准参考，以确保 PTS 得到适当保留。
